Interpretive Summary: Achieving optimum crop yields requires some method of soil compaction management in the Southeastern United States. The most effective and environmentally friendly practice is to conduct an in-row subsoiling operation prior to planting. A study was conducted to determine if in-row subsoiling should be conducted during winter months when time and rainfall are more plentiful or if this practice should be conducted immediately before planting. Preliminary results indicate that maximum soil and crop benefits are mostly found when in-row subsoiling is conducted immediately before planting. Conducting tillage during winter months may be responsible for slightly reducing cover crop yields which in turn may reduce cash crop benefits.

Technical Abstract:
Soil compaction is often treated in the Southeastern United States by using the conservation practice of annual in-row subsoiling. It is common to in-row subsoil immediately prior to planting, however, lack of adequate rainfall in the spring of the year can prevent timely tillage and planting events. It may be helpful to conduct in-row subsoiling during winter months when rainfall is plentiful. An experiment was conducted to determine the effects of elapsed time between in-row subsoiling and planting on a highly compactable Coastal Plain soil. In-row subsoiling was conducted by two different subsoilers, a KMC and a Paratill™, during winter months when time and rainfall was more readily available. Results from this 2 year study (which is continuing) indicated that reduced bulk density, reduced cone index, and slightly increased cash crop and cover crop yields resulted from in-row subsoiling immediately prior to planting.